Conventional film making technology has been revolutionized in recent years by advances in animation and in computer generated images. One of the first processes developed to combine live action with artificial environments was the use of a "blue screen". With this process a live performance is filmed against a blue background, and the background is then photographically replaced with art, inserts or animated characters which then become integrated with the filmed live action.
The animated motion picture "Who Framed Roger Rabbit" was produced with a variety of animation processes, including the blue screen process, and is considered a film animation landmark because of its realism. As may be known, the difficulty of integrating live actors into a bluescreen artificial environment, or of integrating animated characters into live action footage, is the matching of the three dimensional object of the live and artificial action to each other. Human visual acuity is sufficiently precise to detect millimeter offsets in the relative scale, positioning, and dimensional object of the live actor to the animated character. These relative characteristics must be accurately matched to obtain realism and present the viewer with a seamless view of the composite image. If the human actor is to be seen shaking hands with the animated character, then precise relative location of that character is essential to prevent having the two figures overlap or to miss one another.
In "Roger Rabbit" precision matching was achieved by building a composite image, frame by frame, from layers of filmed live action and computer generated images to visually present the animated characters in proper three dimensional object with their companion human actor. If there were only a single frame of action in which an interchange occurred the composition process could be done manually. However there is typically several minutes, or at least seconds, of exchange between the human and animated actors which, at a viewing speed of 24 frames per second (fps) equates to dozens or even hundreds of frames of film.
Since extreme precision in composition is required for realism, and since Roger Rabbit included several minutes of filmed action in which the human actors and animated characters are moving, the composite imagery required an extensive amount of manual labor, and cost. At present the only reliable way of doing this is to use a large amount of labor to do composition manually. There exists, therefore, a need for both method and apparatus which can identify the location of the filmed live elements within the context of a three dimensional setting so to allow automatic determination of the scale and position of the animated elements to be composed within the live scene. Ideally, this must be accomplished in a noninvasive manner, so as not to introduce unwanted elements into the film environment which must later be removed.